Hello! To solve this question, all you have to do is combine like terms. There is a plus sign in from of 4x, so we add. 3x + 4x is 7x. We get 7x - 7 = 28. Now, there is a -7. We need to cancel that out. To do this, we add 7 to both sides. When you do, you get 7x = 35. Divide each side by 7 to isolate the "x". 35/7 is 5. Let's plug it in. 7 * 5 is 35. 35 - 7 is 28. There. x = 5. The solution to the equation is 5.